This invention relates to apparatus for preventing accumulation of ice on structures such as marine vessels.
Structures operating in extremely cold seas such as fishing vessels operating in northern oceans during the winter are likely to gather ice on their superstructure. The problem is especially serious in a strong wind and rough seas when sea water droplets or water splashes contact exposed portions of the upper structure of a vessel. At such times, rapid and extensive formation of ice on parts such as the deck, bridge, handrails, ladders, and deck machinery causes difficulties in operating and navigating the vessel and may cause it to capsize and be lost.
Known techniques for deicing marine structures include (1) spraying with hot water or sea water, (2) heating with electrical cables, and (3) laying rubber mat or sheets of foam material. However, methods (1) and (3) generally yield insufficient effects, and method (2) requires too much electric power. A heater circulating liquid containing anti-freeze is another possible deicing device but would require a long heat-up time if kept off during idle periods or would have very high standby losses if kept warm continuously.
A further consideration in preventing the accumulation of ice on floating marine structures is that these structures are frequently subject to changes in angular orientation--for example, vessels may pitch and roll due to waves.
Accordingly, it is an object of the invention to provide improved apparatus for deicing structures.
It is a more particular object of the invention to provide apparatus for preventing the accumulation of ice on a vessel which can respond quickly and deliver heat efficiently to portions of the vessel requiring it.
It is also an object of the invention to provide heat pipe deicing apparatus for marine structures whose deicing capacity remains substantially unchanged even when the vessel is pitching and rolling.